


Integrals & Issues

by haekass



Series: Fucking Calculus [2]
Category: Super Junior
Genre: M/M, maths warning
Language: English
Status: Completed
Published: 2012-08-04
Updated: 2012-08-04
Packaged: 2020-05-31 10:38:31
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,763
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19424278
Author URL: https://archiveofourown.org/users/haekass/pseuds/haekass
Summary: Lesson two. This time, it's all integration.





	Integrals & Issues

“I still don't get it.”

“What is there not to get? You're taking something easy and making it far too complicated.”

“Hyukkie,” Donghae whined. “I don't get it... just like I didn't get derivatives.”

Hyukjae rolled his eyes affectionately. “Okay, baby, I guess we can start in on the second lesson of Fucking Calculus.” Donghae laughed at the play on words, loving how his boyfriend was so witty, as he was pulled up from the chair by Hyukjae. He hummed happily and snuggled up to the lean frame for a moment before Hyukjae pushed him away. “Let's pretend that we're just waking up in the morning and we're running late.” Donghae scrunched his nose. Hyukjae was hard as hell – in more ways than one – to wake up in the morning. “We have to get dressed quick, so how are you going to do it?”

Donghae ran his greedy eyes over Hyukjae's body. “Say fuck classes and then fuck?”

Hyukjae flicked his forehead, causing him to pout. “Pay attention.”

“I liked the lessons on derivatives better.”

“Well now you have to reverse the process.”

Donghae smirked. “Oh does that mean you're fucking me this time?”

Hyukjae returned the smirk. “If you get this down, baby, I'll fuck you exactly the way you've been begging me to.”

He could have whimpered right then. He loved the soft lovemaking they'd been able to indulge in – a guy needed some romance in his life at times, after all – but what he was starting to crave was being fucked hard, hard enough to blast his mind apart when he came. Blinking, he forced himself to concentrate. The sooner he got this, the sooner that would happen. “So how am I supposed to get you dressed?”

“It's just really derivatives in reverse, baby.”

“But what about that one over k and that constant...”

Hyukjae interrupted him with a kiss. “You're over thinking it. The final product is different, but it's really all the same thing – I'm still going to be wearing a t-shirt and jeans and boxers and socks and shoes. They might _look_ different, but it's the same thing, okay?”

Donghae nodded slowly, his brain finally making a small connection.

“Now pick a problem, and let's work on it, okay?”

Donghae sighed and pointed at a random problem.

Hyukjae smiled. “Don't move.”

Donghae bit his lip, forcing his body to comply with Hyukjae's demand. His boyfriend knew that it turned him on at times to hear the crack of authority, willing Donghae to bend to Hyukjae's will. And Donghae rarely ever said no to it. His breath sped up when Hyukjae stripped out of his clothes and bent to grab a random t-shirt, jeans, and boxers from the mess on the floor.

“Okay get me dressed again,” Hyukjae said. “You've got a derivative, and now you need to go backwards.”

Donghae pouted. “This is totally unsexy, just so you know.”

“But you need to learn it. Stop complaining and do it so I can fuck you until you're screaming.”

“What do I do first?”

“Well first, there's no Chain Rule for anti-derivatives. Multiply the x to the negative three through. What do you have now? Write it down.”

Donghae looked at his notebook. That was fairly simple algebra. “X to the negative two plus x to the negative three,” he said, writing it down.

“Don't forget the integral sign and the dx.”

“Why do I need these again?” Donghae grumbled as Hyukjae pulled the boxers up his lean legs.

“They're like bookends. Think of the integral sign as the time I have to get up and out of bed, everything in the middle is me being in classes and at the studio, and the dx is the time I can come back here and get naked again. You don't want me walking around naked outside, do you?”

Donghae glared at his smirking boyfriend. “About as much as you want me to be naked outside.” He sighed. “Okay, I see why they're there. What's next?”

“Remember how in derivatives we brought the exponent down to multiply and then subtracted one from the exponent itself?”

“Yeah.”

“Now reverse it. Add one to the exponent, and then divide by the new exponent.”

“So it's going to be x to the negative one divided by negative one plus x to the negative two divided by negative two...?”

“Now simplify it.”

Donghae's face cleared as the lesson finally took hold in his brain. “Oh! I get it now!”

Hyukjae chuckled as he smoothed the shirt down, and he grabbed his watch from the desk. “You know how I hate not knowing what time it is, so the C in this case is my watch. I always need my watch when I'm going out, right? So unless there's a definite time – or a definite integral – you need to add my watch to my outfit, okay?”

Donghae nodded, happy that he had finally gotten that down.

“Now I could be mean and have you double check your work by deriving me right back out of my clothes, but I think this lesson is about over. Get naked and get on the bed, baby,” Hyukjae told him while stripping back out of the clothes he had just put on.

Donghae wasted no time in getting himself naked and crawling up on the bed on all fours. He'd been hard ever since Hyukjae had stripped, and he was aching to be fucked hard and fast.

When Hyukjae crawled into bed right behind him, Donghae had to keep himself from moaning. Twisting his head back, he looked pleadingly at his lover, shoving his hips back to make the point.

Hyukjae chuckled. “So impatient, baby.”

Donghae shivered as he felt Hyukjae's long fingers trace his spine, and he couldn't help the whine. “ _Please_ Hyukjae. Just get inside me now, I can't stand this slowness any more.”

The sound of Hyukjae's hand sharply slapping Donghae's ass was quickly followed by the short gasp of air. “You're going to have to tolerate it for a bit more, you know that I will never fuck you without prep.” Hyukjae sat on his feet and tugged Donghae back a little. “Get everything and then come here and give me a kiss.”

Donghae nodded, biting his lower lip. Hyukjae was in control at the moment, control that Donghae had gratefully relinquished to his lover, but could take back at any point in time. He grabbed the bottle of lube and a condom, ducking his head as he placed them with care on the bed, then brushing his lips softly across Hyukjae's.

Hyukjae smiled and cupped the face that he loved so much, his thumbs brushing soft circles across the cheekbones. “I love you, Donghae.”

Donghae's wide smile stole across his face. “I love you too, Hyukkie.”

“Let me prep you, and then I promise you, baby, I'll fuck you hard and fast, okay?”

Donghae nodded, almost ashamed of his earlier outburst. Hyukjae would never do anything to hurt him, and he knew that he would never do anything to hurt Hyukjae either. “How do you want me?”

Hyukjae chuckled a little. “You looked pretty comfortable on your hands and knees. Get back to it.”

In a flash, Donghae was already back to his previous position, his body almost vibrating with the need to be touched. A long, low moan sounded from his throat when he _finally_ was touched, Hyukjae's fingers, cooled with lube, circled around his entrance teasingly before one finger slipped inside him. “More, please,” he pleaded, a happy sigh when Hyukjae pushed another finger inside, then started slowly moving them while scissoring.

His hips rolled back easily on the two fingers, and it wasn't long before Hyukjae was adding the third, and Donghae was almost shaking when Hyukjae added the fourth. Pushing back greedily, wanton moans spilled from his throat as fingers brushed past his prostate, his legs spreading wider in invitation.

“Stay right there, baby,” Hyukjae told him, pulling his fingers out after a few minutes of being to move them smoothly in and out.

Donghae's breath caught. _Finally_ he was going to be fucked exactly how he'd been wanting. Forcing his body to not move, he waited, shaking with anticipation. Hyukjae teased him for a brief second, then carefully pushed the head of his cock inside.

“Ready baby?” Hyukjae asked, his voice strained.

“ _Yes_ ,” Donghae hissed. His next breath was taken away on a scream as Hyukjae buried himself inside Donghae's body with one thrust. Donghae reflexively clenched, hearing Hyukjae moan behind him, the lean fingers digging into his hips. His body shuddered as he finally relaxed around Hyukjae.

The first stroke was slow, teasing, and had Donghae shaking. Hyukjae grinned ferally as he pushed back inside roughly, hearing Donghae's pleased half scream as the younger shoved eagerly back.

Donghae moaned continuously as Hyukjae thrust into him, feeling the pleasure build with every brush against his prostate, and he reached down to give himself the final few strokes he would need to come when Hyukjae pulled his hand away, pulling it behind his back.

“No, baby. You'll come without touching yourself tonight.”

Donghae balanced himself as well as he could on one hand, adjusting his position just the slightest bit. But that little adjustment had Hyukjae hitting his prostate with the next thrust, and his entire body shook with the absolute _need_ to come, another scream coming from his throat.

“Please, please, please, oh God _please_ let me come,” Donghae chanted as Hyukjae roughly pounded into him, hitting his prostate unerringly with each thrust. “ _Please Hyukjae_ ,” he whined.

Hyukjae grunted and then reached down, tugging Donghae's length in time with each thrust.

Donghae's body rippled with pleasure as he was finally getting the stimulation he craved. Shoving back, Hyukjae's long, lean fingers brushed over the sensitive head of his dick, and he screamed Hyukjae's name as he came.

Vaguely, he could feel Hyukjae riding out his own orgasm, each new thrust a shock to his oversensitive system. He felt Hyukjae finally slip out of him and he rolled onto his side, panting. Hyukjae spooned up behind him, rubbing soft, soothing circles on his stomach.

“That was good,” Donghae murmured, a smile spreading across his face.

Hyukjae chuckled. “Think you can remember integrals now?”

“I always remember your lessons, baby.”

Hyukjae twined their fingers together, humming happily. “As long as you always remember I love you.”

Donghae rolled his head back and pressed a kiss to the plump lips. “That's one lesson I'm never going to need to be reminded of.”


End file.
